HEMPSTEAD, Texas (AP) ' Authorities say a 22-year-old man charged in the fatal shootings of his parents and brother at their Southeast Texas home had been studying serial killers and mass shootings such as the Columbine attack and had hoped to carry out another act of public violence.

Police arrested Trey Sesler on Tuesday after finding his family members' bodies at their home in Waller, about 40 miles northwest of Houston. Police said Thursday they've also recovered ammunition and about six weapons, including long rifles.